1. Field of the Invention
The invention disclosed and claimed herein generally pertains to a method for enabling specified file content, in a content data network, to be distributed from a particular selected depot server to multiple clients. More particularly, the invention pertains to a method of the above type wherein the file content can be delivered to a comparatively large number of clients, who all request the content from the same depot server simultaneously, or within a narrow time window. Even more particularly, the invention pertains to a method of the above type wherein clients are informed that the specified file content is being made available for downloading, when the content is first uploaded to a depot server of the content data network, and multiple clients can all get the file content from a single source.
2. Description of the Related Art
The Internet was designed to provide a core network that is relatively simple, by moving components that require more intelligence to network end-points, such as to hosts and clients. The core network is therefore specialized, simplified and optimized to transport only data packets. In view of this, content delivery networks (CDN) have been developed to augment the end-to-end transport network, by using intelligent applications that employ techniques designed to optimize delivery content. A content delivery network is generally a system of computers that are networked together across the Internet, and cooperate transparently to deliver content such as large media data files to end users.
In making data file content or the like available for downloading to clients who request it, it is generally advantageous to position the content in locations that are close to the clients. The content can be uploaded or published from a source to a depot server repository, and can then be replicated from the repository to other depot servers. In order to minimize wide area network (WAN) bandwidth, the replication to other depot servers is usefully fanned out in stages by the distribution application, first to the closest depot servers, and then to the depot servers that are closest to those servers. It would usually require substantial WAN bandwidth to download the specified content directly to each of the clients from the original source location. Accordingly, in an arrangement wherein a number of clients are located at an isolated branch office or the like, a single depot server is also located at the branch office, proximate to each of the clients. The content is first replicated at this depot server, and then downloaded to each client over a local area network (LAN) associated with the branch office.
In one current approach, clients are told to download specified file content right after the content has initially been loaded into the depot server repository, as described above. In this case, because of the inherent delay in replicating the content to other depot servers, many or all of the clients will immediately go to the initially loaded depot server repository, where the entire content will definitely be available. This situation can result in conflicts and delays, and extensive use of WAN bandwidth.
In an alternative approach, a particular depot server will broadcast the availability of specified content to its associated clients, after the content has been replicated into the particular server. However, this procedure requires a client to know that it is interested in the specified content, and also requires a client to be listening for the availability message.
It would generally be beneficial to improve efficiency in providing specified content to multiple clients, such as to multiple clients from a single branch office source. A useful goal would be to download the specified file content into a branch office source only once. All the clients at the branch would then wait to get the file content from that source.